JPH06316541A - Tolan derivative and liquid crystal composition containing the sane and liquid crystal display element using the composition - Google Patents

Abstract

PURPOSE:To provide a new tolan derivative, a new liquid crystal compound, good in compatibility with several kinds of nematic liquid crystal compounds or non-liquid crystal compounds, capable of obtaining a liquid crystal composition broad in practical temperature range and large in DELTAn value by its mixing. CONSTITUTION:The tolan derivative of formula 1 (R is a 1-10C straight chain alkyl; X1-X4 are each F or H, at least one of them being F; Y is a nitrile or 1-10C straight chain alkyl), e.g. 1-(4'-propylphenylethynyl)-4-(4''- pentylphenylethyl)-2--fluorobenzene. The compound of the formula 1 can be obtained by the following process: a compound of formula 4 is obtained from a compound of formula 2 through two steps; a compound of formula 7 is obtained from a compound of formula 5 through two steps; subsequently, a compound of formula 8 is obtained from the compound of the formula 4 and the compound of the formula 7; a compound of formula 11 is obtained from a compound of formula 9 through two steps; finally, the compound of the formula 8 is reacted with the compound of the formula 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel tolan derivative used as an electro-optical display material, a liquid crystal composition containing the same, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art A liquid crystal display device utilizes the electro-optical effect of liquid crystal, and as a currently used display system, a twisted nematic (hereinafter referred to as TN) type or a super twisted nematic (a twisted nematic having a larger twist angle) is used. Hereinafter referred to as STN) type. The characteristics required for these display systems are listed below.

1. No coloration and stable to heat, light, electrical and chemical.

2. Wide operating temperature range.

3. A high electro-optical response speed.

4. The driving voltage is low.

5. The voltage-light transmittance characteristic has a steep rise and the threshold voltage (hereinafter referred to as Vth) has little temperature dependence.

6. Wide viewing angle range.

Among these characteristics, many liquid crystals satisfying one characteristic are known, but no liquid crystal compound satisfying the characteristics of 2 or less with a single component is known. Therefore, in order to obtain these characteristics, a liquid crystal composition in which several kinds of nematic liquid crystal compounds or non-liquid crystal compounds are mixed is used. In order to satisfy the characteristics of 2 among these, the crystal phase-
A liquid crystal compound having a low nematic liquid crystal phase transition point (hereinafter referred to as C-N point) and a high nematic liquid crystal phase-isotropic liquid transition point (hereinafter referred to as NI point), resulting in a wide nematic liquid crystal phase temperature range. Is required. In order to satisfy the characteristic of 3, there is the following relational expression between the response speed (hereinafter referred to as τ), the viscosity coefficient (hereinafter referred to as η), and the cell gap (hereinafter referred to as d), and the response speed is increased. In order to do so, it is necessary to reduce d by a small τ∝ηd ² . By the way, in a practically used cell, the value of Δn · d (Δn is a refractive index anisotropy, the same applies hereinafter) is constant in order to prevent the generation of interference fringes on the cell surface, which causes the cell appearance to be impaired. Since the value is set, the value of d can be reduced by using a material having a large Δn, and as a result, the response speed can be increased.
In order to satisfy the characteristics of 2 and 3 at the same time, it has already been adv. In Liquid Crystal Research and Applicat as a liquid crystal material having a wide nematic liquid crystal range and large Δn.
ion (edited by L. Bata) .Oxford: Pergamon Press; Budape
st: Akademiai Kiado 1980, S.1029, Tolan derivatives described in JP-A-1-305040 and the like are known.

[0010]

[Table 1]

Among these, the compounds a and b show a wide nematic range and no smectic layer appears, and the compounds u, d and o have extremely large Δn and have a viscosity as a tricyclic structure compound. Is low and high N
It is described in each document that it has a −I point and has desirable characteristics as a liquid crystal component in a well-balanced manner.

[0012]

However, among these compounds, the compounds a) and b) are expected to have a small Δn because of the presence of a chlorine group or a nitrile group in the side chain in the skeleton. In addition, the compounds C, N, and E have a C-N point of 15
Since it is 0 ° C. or higher, it seems that there is a problem in compatibility with other liquid crystals. Therefore, the present invention responds to the demand in such an actual situation, and its purpose is to have good compatibility with several kinds of nematic liquid crystal compounds or non-liquid crystal compounds, and by mixing, a wide practical temperature range and a large Δn value can be obtained. A novel liquid crystal compound capable of obtaining a liquid crystal composition is provided. Further, it is to provide a liquid crystal display element having a wide practical temperature range and a high response speed by using them.

[0013]

The present invention has the general formula

[0014]

[Chemical 16]

(In the above formula, R represents a straight-chain alkyl group having 1 to 10 carbon atoms, and X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X Represents a fluorine atom, and Y represents a nitrile group or has 1 carbon atom.
10 represents a linear alkyl group of 10), a tolan derivative, a liquid crystal composition containing the same, and a liquid crystal display device using the same. Inventive compound (1)
Can be obtained by the following manufacturing method.

[0016]

[Table 2]

(Here, R represents a straight-chain alkyl group having 1 to 10 carbon atoms, and X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is at least one. Represents a fluorine atom, and Y is a nitrile group or has 1 carbon atom.
10 represents a linear alkyl group) Step 1) Compound (2)
Is reacted with 3-methyl-1-butyn-3-ol in the presence of bis (triphenylphosphine) palladium (II) chloride, triphenylphosphine and copper (I) iodide in triethylamine to give compound (3) To get

Step 2) The compound (3) is reacted with sodium hydride in toluene to obtain the compound (4).

Step 3) Compound (5) is reacted with iodine monochloride in acetic acid in the presence of pyridine to obtain compound (6).

Step 4) Compound (6) is reacted with sodium nitrite and sulfuric acid in acetic acid to form a diazonium salt,
The compound (7) is obtained by reacting copper bromide with hydrobromic acid.

However, when the compound (6) is on the market, step 3 is not necessary, and when the compound (7) is on the market, steps 3 and 4 are not necessary.

Step 5) Compound (4) in bis (triphenylphosphine) palladium (II) in diethylamine
Compound (8) is obtained by reacting with compound (7) in the presence of chloride and copper (I) iodide.

Step 6) The compound (9) is added to bis (triphenylphosphine) palladium (I) in triethylamine.
I) Compound (10) is obtained by reacting with 3-methyl-1-butyn-3-ol in the presence of chloride, triphenylphosphine and copper (I) iodide.

Step 7) Compound (10) is reacted with sodium hydride in toluene to obtain compound (11).

Step 8) Compound (8) was added to bis (triphenylphosphine) palladium (I
I) Compound (1) is obtained by reacting with compound (11) in the presence of chloride, triphenylphosphine and copper (I) iodide.

Examples of the components of the liquid crystal composition which becomes the base when the tolan derivative of the present invention is mixed include the compounds shown below, but the present invention is not limited to these and all conventional liquid crystal compounds or analogues thereof can be used. It has good compatibility with the compound, the obtained liquid crystal composition has a wide operating temperature range,
It has a characteristic that n is large.

[0027]

[Table 3]

(Wherein R and R'represent an alkyl group, an alkoxy group, an alkoxymethylene group, a nitrile group or a fluoro group, the phenylene group may have a halogen substituent at the 2- or 3-position, and a cyclohexane ring. The liquid crystal composition can be mixed with the compound of the present invention in an amount of 1 to 50% by weight, but 3 to 30 in consideration of crystal precipitation in a low temperature region.
A weight percent range is particularly preferred.

A liquid crystal display device using a liquid crystal composition containing at least one kind of the compound of the present invention is suitable for a liquid crystal display device using a time-division driving system, and particularly TN type and S type.
High time-division driving is possible in a TN type liquid crystal display element.

[0030]

The present invention will be described in more detail with reference to the following examples.

(Example 1) [Synthesis of compound (1-a)] 1- (4'-propylphenylethynyl) -4- (4 ")
-Pentylphenylethynyl) -2-fluorobenzene Step 1) 60 g of 1-bromo-4-propylbenzene, 38 g of 3-methyl-1-butyn-3-ol, 1.3 g of triphenylphosphine, bis ( 0.7 g of triphenylphosphine) palladium (II) chloride was dissolved in 260 ml of triethylamine, and copper (I) iodide was added to the solution.
0.2 g was added. After stirring at room temperature for 1 hour, the mixture was stirred at 90 ° C. for 5 hours. The precipitated crystals were filtered, triethylamine was distilled off, and the crystals were extracted with chloroform. After washing twice with 10% hydrochloric acid and twice with water, chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography to give 3-methyl-1- (4'-propylphenyl) -1-butyne-
37 g of 3-ol was obtained.

Step 2) 3-methyl-1-in a nitrogen atmosphere
(4'-Propylphenyl) -1-butyn-3-ol
33 g was dissolved in 320 ml toluene, and 2 g of sodium hydride (60% in paraffin liquid) was added thereto. The mixture was stirred at 60 ° C for 6 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, and washed with water three times. After distilling off toluene and chloroform, vacuum distillation (bp 60 to 63 ° C./4 mmHg) was carried out to obtain 16 g of 4-propylphenylacetylene.

Steps 3, 4) 4-Bromo-2-fluoro-
Since 1-iodobenzene is commercially available, this step is not necessary.

Step 5) 33 g of 4-bromo-2-fluoro-1-iodobenzene in 37 ml of diethylamine in a nitrogen atmosphere.
Was dissolved in 0.1 g of bis (triphenylphosphine) palladium (II) chloride and 0.1 g of copper (I) iodide, and the mixture was stirred. The flask was cooled to 5 ° C. or lower, and 16 g of 4-propylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction mixture was concentrated with hydrochloric acid (23 ml) and ice (150 ml).
Pour into the mixing of g. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (bp19
After performing 0 to 200 ° C./4 mmHg), recrystallization from a mixed solvent of acetone and methanol was performed to obtain 23 g of 4-bromo-2-fluoro-4′-propyltolan.

Step 6) 102 g of 1-bromo-4-pentylbenzene, 3-methyl-1-butyne-3-in a nitrogen atmosphere
All 38 g, triphenylphosphine 2 g, bis (triphenylphosphine) palladium (II) chloride
1 g was dissolved in 390 ml of triethylamine, and 0.3 g of copper (I) iodide was added therein. After stirring at room temperature for 1 hour, the mixture was stirred at 90 ° C. for 5 hours. The precipitated crystals were filtered, triethylamine was distilled off, and the crystals were extracted with chloroform. 10% hydrochloric acid twice,
After washing twice with water, chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography to give 3-methyl-1- (4'-pentylphenyl) -1.
82 g of butyn-3-ol were obtained.

Step 7) 3-methyl-1-in a nitrogen atmosphere
(4'-Pentylphenyl) -1-butyn-3-ol
82 g was dissolved in 900 ml of toluene, and 5.6 g of sodium hydride (60% in paraffin liquid) was added therein. 6 at 60 ° C
Stir for hours. The reaction solution was poured into 500 ml of water, extracted with chloroform, and washed with water three times. After distilling off toluene and chloroform, vacuum distillation (bp 85-90 ° C / 3mmHg)
After that, 48 g of 4-pentylphenylacetylene was obtained.

Step 8) In a nitrogen atmosphere, 3.8 g of 4-bromo-2-fluoro-4'-propyltolan, 2.1 g of 4-pentylphenylacetylene, 0.03 of triphenylphosphine.
5 g, bis (triphenylphosphine) palladium (I
I) 0.02 g of chloride was dissolved in 27 ml of triethylamine, and 0.01 g of copper (I) iodide was added therein. afterwards,
Reflux for 5 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, washed twice with water, and then chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from acetone to give 1-
(4'-Propylphenylethynyl) -4- (4 "-pentylphenylethynyl) -2-fluorobenzene 1.4
g was obtained. The C-N point of this compound is 81.3 ° C, and N-
The point I was 202.7 ° C.

The following compounds were synthesized by the same method.

1,4-bis (4'-methylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Ethylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2-fluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Methylphenylethynyl) -2-fluorobenzene 1,4-bis (4′-ethylphenylethynyl) -2-
Fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Methylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Ethylphenylethynyl) -2-fluorobenzene C-N point 150.3 ° C NI point 214.1 ° C 1,4-bis (4'-propylphenylethynyl) -2
-Fluorobenzene C-N point 147.0 ° C N-I point 220.0 ° C 1- (4'-propylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2-fluorobenzene C-N point 112.4 ° C N-I point 203.7 ° C 1- (4'-propylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2-fluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Methylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Ethylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2-fluorobenzene C-N point 112.6 ° C. NI point 201.2 ° C. 1,4-bis (4′-butylphenylethynyl) -2-
Fluorobenzene C-N point 91.5 ° C NI point 185.6 ° C 1- (4'-butylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2-fluorobenzene C-N point 78.5 ° C N-I point 186.9 ° C 1- (4'-butylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Methylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Ethylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Propylphenylethynyl) -2-fluorobenzene C-N point 88.3 ° C NI point 203.0 ° C 1- (4'-pentylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2-fluorobenzene C-N point 82.4 ° C N-I point 187.7 ° C 1,4-bis (4'-pentylphenylethynyl) -2
-Fluorobenzene C-N point 89.2 ° C N-I point 189.0 ° C 1- (4'-pentylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2-fluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Methylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Ethylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Propylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Pentylphenylethynyl) -2-fluorobenzene 1,4-bis (4'-hexylphenylethynyl) -2
-Fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Methylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Ethylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Propylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Pentylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2-fluorobenzene 1,4-bis (4'-heptylphenylethynyl) -2
-Fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Methylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Ethylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Propylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Pentylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2-fluorobenzene 1,4-bis (4'-octylphenylethynyl) -2
-Fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Methylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Ethylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2-fluorobenzene 1,4-bis (4′-nonylphenylethynyl) -2-
Fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Methylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Ethylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2-fluorobenzene 1,4-bis (4′-decylphenylethynyl) -2-
Fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2-fluorobenzene (Example 2) [Synthesis of compound (1-b)] 1- (4'-pentylphenylethynyl) -4- (4 "
Preparation of -cyanophenylethynyl) -2-fluorobenzene Steps 1 and 2) 4-pentylphenylacetylene was synthesized in the same manner as in Steps 6 and 7 of Example 1.

Steps 3, 4) 4-Bromo-2-fluoro-
Since 1-iodobenzene is commercially available, this step is not necessary.

Step 5) In a nitrogen atmosphere, 57 g of 4-bromo-2-fluoro-1-iodobenzene was added to 66 ml of diethylamine.
Was dissolved in 0.5 g of bis (triphenylphosphine) palladium (II) chloride and 0.5 g of copper (I) iodide, and the mixture was stirred. The flask was cooled to 5 ° C. or lower, and 36 g of 4-pentylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction solution was concentrated hydrochloric acid 40 ml and ice 30 g.
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (bp205
˜210 ° C./3 mmHg), and then recrystallized from a mixed solvent of acetone and methanol to obtain 27 g of 4-bromo-2-fluoro-4′-pentyltran.

Step 6) 4-bromobenzonitrile 30 g, 3-methyl-1-butyn-3-ol 13.4 in a nitrogen atmosphere
g, triphenylphosphine 0.7g, bis (triphenylphosphine) palladium (II) chloride 0.3g
Was dissolved in 140 ml of triethylamine, and 0.1 g of copper (I) iodide was added thereto. After stirring for 1 hour at room temperature, 5 at 90 ° C
Stir for hours. The precipitated crystals were filtered, triethylamine was distilled off, and the crystals were extracted with chloroform. After washing twice with 10% hydrochloric acid and twice with water, chloroform was distilled off. The residue was distilled under reduced pressure (140-160 ° C / 5mmHg) to give 3-methyl-1- (4'-
23.5 g of cyanophenyl) -1-butyn-3-ol was obtained.

Step 7) 3-methyl-1-in a nitrogen atmosphere
(4'-Cyanophenyl) -1-butyn-3-ol 2
3.5 g was dissolved in 250 ml of toluene, and 1.6 g of sodium hydride was added therein. The mixture was stirred at 80 to 90 ° C for 4 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, and washed with water 3 times.
I went there. After distilling off toluene and chloroform, the residue was recrystallized from methanol to obtain 9.9 g of 4-cyanophenylacetylene.

Step 8) In a nitrogen atmosphere, 5.2 g of 4-bromo-2-fluoro-4'-pentyltran, 1.9 g of 4-cyanophenylacetylene, 0.06 of triphenylphosphine.
g, bis (triphenylphosphine) palladium (I
I) 0.04 g of chloride was dissolved in 33 ml of triethylamine, and 0.01 g of copper (I) iodide was added therein. afterwards,
Reflux for 5 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, washed twice with water, and then chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from a mixed solvent of acetone and chloroform to give 1- (4'-pentylphenylethynyl) -4- (4 "-cyanophenylethynyl) -2-.
2.7 g of fluorobenzene was obtained. The C-N point of this compound was 150.5 ° C, and the NI point was 256.5 ° C.

The following compounds were synthesized by the same method.

1- (4'-methylphenylethynyl)-
4- (4 "-cyanophenylethynyl) -2-fluorobenzene 1- (4'-ethylphenylethynyl) -4- (4"-
Cyanophenylethynyl) -2-fluorobenzene 1- (4'-propylmethylphenylethynyl) -4-
(4 "-Cyanophenylethynyl) -2-fluorobenzene 1- (4'-butylphenylethynyl) -4- (4"-
Cyanophenylethynyl) -2-fluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Cyanophenylethynyl) -2-fluorobenzene 1- (4'-decylphenylethynyl) -4- (4 "-
Cyanophenylethynyl) -2-fluorobenzene (Example 3) [Synthesis of compound (1-c)] 4- (4'-propylphenylethynyl) -1- (4 "
Preparation of -cyanophenylethynyl) -2-fluorobenzene Steps 1 and 2) 4-pentylphenylacetylene was synthesized in the same manner as in Steps 6 and 7 of Example 1.

Step 3) This step is not necessary since 2-fluoro-4-iodoaniline is commercially available.

Step 4) 51.2 g of sodium nitrite is added to sulfuric acid 39
It was dissolved in 0 ml and then 454 ml acetic acid was added below 10 ° C.
Keep the solution at 20-25 ° C for 1 hour to 2-fluoro-4-
124 g of iodoaniline was added and stirred for 2 hours. The solution was added dropwise to a solution prepared by dissolving 130 g of copper bromide in 390 ml of 48% hydrobromic acid and stirred overnight. Then, 1000 ml of water was added and the mixture was extracted with chloroform and washed with water three times. Chloroform was distilled off, and the residue was distilled under reduced pressure (bp 120 to 125 ° C / 13 mmHg) and recrystallized from methanol to give 1-bromo-2-fluoro-4.
-114 g of iodobenzene are obtained.

Step 5) 1-bromo-2-fluoro-4-iodobenzene (15 g) in a nitrogen atmosphere and diethylamine (17 ml)
Was dissolved in 0.12 g of bis (triphenylphosphine) palladium (II) chloride and 0.12 g of copper (I) iodide, and the mixture was stirred. The flask was cooled to 5 ° C. or lower, and 8 g of 4-propylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction solution was mixed with concentrated hydrochloric acid (10 ml) and ice (50 g).
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. The residue was recrystallized from a mixed solvent of acetone and methanol to give 4-bromo-3-
11 g of fluoro-4'-propyl ruthran was obtained.

Steps 6 and 7) 4-cyanophenylacetylene was synthesized in the same manner as in Steps 6 and 7 of Example 2.

Step 8) In a nitrogen atmosphere, 4-bromo-3-fluoro-4'-propyltolan 4.8 g, 4-cyanophenylacetylene 1.9 g, triphenylphosphine 0.06
g, bis (triphenylphosphine) palladium (I
I) 0.04 g of chloride was dissolved in 33 ml of triethylamine, and 0.01 g of copper (I) iodide was added therein. afterwards,
Reflux for 5 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, washed twice with water, and then chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from a mixed solvent of acetone and chloroform to give 4- (4'-propylphenylethynyl) -1- (4 "-cyanophenylethynyl) -2-.
3.4 g of fluorobenzene was obtained. The C-N point of this compound was 163.6 ° C, and the NI point was 275.3 ° C.

The following compounds were synthesized by the same method.

4- (4'-methylphenylethynyl)-
1- (4 "-cyanophenylethynyl) -2-fluorobenzene 4- (4'-ethylphenylethynyl) -1- (4"-
Cyanophenylethynyl) -2-fluorobenzene 4- (4'-butylphenylethynyl) -1- (4 "-
Cyanophenylethynyl) -2-fluorobenzene 4- (4'-pentylphenylethynyl) -1- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 4- (4'-hexylphenylethynyl) -1- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 4- (4'-heptylphenylethynyl) -1- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 4- (4'-octylphenylethynyl) -1- (4 "
-Cyanophenylethynyl) -2-fluorobenzene 4- (4'-nonylphenylethynyl) -1- (4 "-
Cyanophenylethynyl) -2-fluorobenzene 4- (4'-decylphenylethynyl) -1- (4 "-
Cyanophenylethynyl) -2-fluorobenzene (Example 4) [Synthesis of compound (1-d)] 5- (4'-propylphenylethynyl) -2- (4 "
-Butylphenylethynyl) -1,3-difluorobenzene production Steps 1 and 2) 4-Propylphenylacetylene was synthesized in the same manner as in Steps 1 and 2 of Example 1.

Step 3) 38 g of 2,6-difluoroaniline
Was dissolved in 120 ml of acetic acid, 25 g of pyridine was added, and the mixture was stirred.
A mixed solution prepared by dissolving 50 g of iodine monochloride in 30 ml of acetic acid was added dropwise thereto. After stirring at room temperature for 1 hour, the mixture was stirred at 70 to 80 ° C for 2 hours. Then, the reaction solution was poured into water, and the precipitated crystals were filtered and washed with water. The crystals were dissolved in chloroform, washed twice with water, twice with a 10% aqueous potassium hydroxide solution and twice with water, and then the chloroform was distilled off. Vacuum distillation of the residue (bp
120-130 ° C./20 mmHg) and recrystallized from methanol to obtain 44 g of 4-iodo-2,6-difluoroaniline.

Step 4) 17 g of sodium nitrite and 130 m of sulfuric acid
150 ml of acetic acid was added below 10 ° C. The solution was kept at 20 to 25 ° C for 1 hour, and 4-iodo-2,6-
44 g of difluoroaniline was added and stirred for 2 hours. The solution was added dropwise to a solution in which 43 g of copper bromide was dissolved in 125 ml of 48% hydrobromic acid, and the mixture was stirred overnight. Then, 300 ml of water was added and the mixture was extracted with chloroform and washed with water three times. Chloroform was distilled off and recrystallized from methanol to give 2-bromo-1,3
38 g of difluoro-4-iodobenzene were obtained.

Step 5) 2-bromo-1,3 in a nitrogen atmosphere
20 g of -difluoro-4-iodobenzene was dissolved in 30 ml of diethylamine, to which 0.06 g of bis (triphenylphosphine) palladium (II) chloride and 0.06 g of copper (I) iodide were added and stirred. The flask was cooled to 5 ° C or lower, and 10 g of 4-propylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction mixture was concentrated with hydrochloric acid (15 ml) and ice (30 g).
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (bp185
˜192 ° C./4 mmHg) and then recrystallized from a mixed solvent of acetone and methanol to obtain 12 g of 4-bromo-3,5-difluoro-4′-propyltran.

Step 6) 235 g of 1-bromo-4-butylbenzene, 139 g of 3-methyl-1-butyn-3-ol, 4.8 g of triphenylphosphine, bis (triphenylphosphine) palladium (II) in a nitrogen atmosphere. Chloride
2.8 g was dissolved in 1,000 ml of triethylamine, and 0.8 g of copper (I) iodide was added therein. After stirring for 1 hour at room temperature, 90
The mixture was stirred at 0 ° C for 5 hours. The precipitated crystals were filtered, triethylamine was distilled off, and the crystals were extracted with chloroform. 10% hydrochloric acid 2
After washing twice with water and chloroform, the chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography to give 3-methyl-1- (4'-butylphenyl) -1.
100 g of butyn-3-ol were obtained.

Step 7) 3-methyl-1-in a nitrogen atmosphere
(4'-Butylphenyl) -1-butyn-3-ol 10
0 g was dissolved in 900 ml of toluene, and 5.7 g of sodium hydride (60% in paraffin liquid) was added thereto. 6 at 60 ° C
Stir for hours. The reaction solution was poured into 500 ml of water, extracted with chloroform, and washed with water three times. After distilling off toluene and chloroform, vacuum distillation (bp62 ~ 65 ℃ / 3mmHg) is performed. 4-
63 g of butylphenylacetylene was obtained.

Step 8) 4-bromo-3,5 in a nitrogen atmosphere
-Difluoro-4'-propyltolan 5.0 g, 4-butylphenylacetylene 2.4 g, triphenylphosphine 0.06 g, and bis (triphenylphosphine) palladium (II) chloride 0.04 g were dissolved in triethylamine 33 ml, and then dissolved therein. 0.01 g of copper (I) iodide was added. Then, reflux was performed for 5 hours. The reaction solution was concentrated hydrochloric acid 16 ml and ice 30 g
Pour into the mixture, extract with chloroform, wash twice with water,
Chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from acetone to give 5- (4'-propylphenylethynyl) -2- (4 "-butylphenylethynyl) -1,3.
-3.5 g of difluorobenzene are obtained. C- of this compound
The N point was 120.4 ° C and the NI point was 181.9 ° C.

The following compounds were synthesized by the same method.

5- (4'-methylphenylethynyl)-
2- (4 "-methylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4"-
Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-methylphenylethynyl) -2- (4 "-
Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4 "-
Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Propylphenylethynyl) -1,3-difluorobenzene C-N point 155.9 ° C N-I point 196.9 ° C 5- (4'-propylphenylethynyl) -2- (4 "
-Pentylphenylethynyl) -1,3-difluorobenzene C-N point 79.6 ° C N-I point 182.7 ° C 5- (4'-propylphenylethynyl) -2- (4 "
-Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Propylphenylethynyl) -1,3-difluorobenzene C-N point 115.5 ° C N-I point 180.6 ° C 5- (4'-butylphenylethynyl) -2- (4 "-
Butylphenylethynyl) -1,3-difluorobenzene C-N point 96.2 ° C N-I point 167.7 ° C 5- (4'-butylphenylethynyl) -2- (4 "-
Pentylphenylethynyl) -1,3-difluorobenzene C-N point 78.3 ° C N-I point 168.7 ° C 5- (4'-butylphenylethynyl) -2- (4 "-
Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Decylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Methylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Ethylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Propylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Butylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Pentylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Hexylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Heptylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Octylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Nonylphenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Decylphenylethynyl) -1,3-difluorobenzene (Example 5) [Synthesis of compound (1-e)] 5- (4'-propylphenylethynyl) -2- (4 "
Production of -cyanophenylethynyl) -1,3-difluorobenzene Steps 1 and 2) 4-Propylphenylacetylene was synthesized in the same manner as in Steps 1 and 2 of Example 1.

Steps 3 and 4) 2-Bromo-1,3-difluoro-4-iodobenzene was synthesized in the same manner as in Steps 3 and 4 of Example 4.

Step 5) 2-bromo-1,3 in a nitrogen atmosphere
20 g of -difluoro-4-iodobenzene was dissolved in 30 ml of diethylamine, to which 0.06 g of bis (triphenylphosphine) palladium (II) chloride and 0.06 g of copper (I) iodide were added and stirred. The flask was cooled to 5 ° C or lower, and 10 g of 4-propylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction mixture was concentrated with hydrochloric acid (15 ml) and ice (30 g).
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (b.p. 185-1
After carrying out at 92 ° C./4 mmHg), it was recrystallized from a mixed solvent of acetone and methanol to obtain 12 g of 4-bromo-3,5-difluoro-4′-propyltran.

Steps 6 and 7) 4-cyanophenylacetylene was synthesized in the same manner as in Steps 6 and 7 of Example 2.

Step 8) 4-bromo-3,5 in a nitrogen atmosphere
5.0 g of -difluoro-4'-propyltolan, 1.9 g of 4-cyanophenylacetylene, 0.06 g of triphenylphosphine, 0.04 g of bis (triphenylphosphine) palladium (II) chloride are dissolved in 33 ml of triethylamine. 0.01 g of copper (I) iodide was added. Then, reflux was performed for 5 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, washed twice with water, and then chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from a mixed solvent of acetone and chloroform to give 5- (4'-propylphenylethynyl) -2- (4 "-cyanophenylethynyl)-.
0.7 g of 1,3-difluorobenzene was obtained. The C-N point of this compound was 147.5 ° C, and the NI point was 263.9 ° C.

The following compounds were synthesized by the same method.

5- (4'-methylphenylethynyl)-
2- (4 "-cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4"-
Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-butylphenylethynyl) -2- (4 "-
Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Cyanophenylethynyl) -1,3-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Cyanophenylethynyl) -1,3-difluorobenzene (Example 6) [Synthesis of compound (1-f)] 1,4-bis (4'-propylphenylethynyl)-
Production of 2,5-difluorobenzene Steps 1 and 2) 4-Propylphenylacetylene was synthesized in the same manner as in Steps 1 and 2 of Example 1.

Step 3) 38 g of 2,5-difluoroaniline
Was dissolved in 120 ml of acetic acid, 25 g of pyridine was added, and the mixture was stirred.
A mixed solution prepared by dissolving 50 g of iodine monochloride in 30 ml of acetic acid was added dropwise thereto. After stirring at room temperature for 1 hour, the mixture was stirred at 70 to 80 ° C for 2 hours. Then, the reaction solution was poured into water, and the precipitated crystals were filtered and washed with water. The crystals were dissolved in chloroform, washed twice with water, twice with a 10% aqueous potassium hydroxide solution and twice with water, and then the chloroform was distilled off. Vacuum distillation of the residue (bp
130-140 ° C./20 mmHg) and recrystallized from methanol to obtain 4-iodo-2,5-difluoroaniline (50 g).

Step 4) 19 g of sodium nitrite and 148 m of sulfuric acid
170 ml of acetic acid was added below 10 ° C. Keep the solution at 20-25 ° C for 1 hour to 4-iodo-2,5-
50 g of difluoroaniline was added and stirred for 2 hours. The solution was added dropwise to a solution prepared by dissolving 49 g of copper bromide in 142 ml of 48% hydrobromic acid and stirred overnight. Then, 300 ml of water was added and the mixture was extracted with chloroform and washed with water three times. Chloroform was distilled off and recrystallized from methanol to give 2-bromo-1,4
45 g of difluoro-4-iodobenzene were obtained.

Step 5) 2-bromo-1,4 in a nitrogen atmosphere
19 g of -difluoro-4-iodobenzene was dissolved in 28 ml of diethylamine, to which 0.06 g of bis (triphenylphosphine) palladium (II) chloride and 0.06 g of copper (I) iodide were added and stirred. The flask was cooled to 5 ° C or lower, and 10 g of 4-propylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction mixture was concentrated with hydrochloric acid (15 ml) and ice (30 g).
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (b.p170-1
80 ° C./4 mmHg) was performed to obtain 16 g of 4-bromo-2,5-difluoro-4′-propyltran.

Steps 6 and 7) 4-Propylphenylacetylene was synthesized in the same manner as in Steps 1 and 2 of Example 1.

Step 8) 4-bromo-2,5 in a nitrogen atmosphere
-Difluoro-4'-propyltolan 5.0 g, 4-propylphenylacetylene 2.1 g, triphenylphosphine 0.06 g, and bis (triphenylphosphine) palladium (II) chloride 0.04 g were dissolved in triethylamine 33 ml, and then dissolved therein. 0.01 g of copper (I) iodide was added. Then, reflux was performed for 5 hours. The reaction solution was concentrated hydrochloric acid 16 ml and ice 30 g
Pour into the mixture, extract with chloroform, wash twice with water,
Chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from acetone to obtain 2.6 g of 1,4-bis (4'-propylphenylethynyl) -2,5-difluorobenzene. The C-N point of this compound was 153.4 ° C, and the NI point was 197.7 ° C.

The following compounds were synthesized by the same method.

1,4-bis (4'-methylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Ethylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-methylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-ethylphenylethynyl) -2,
5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Propylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Butylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-ethylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Butylphenylethynyl) -2,5-difluorobenzene C-N point 117.7 ° C N-I point 183.8 ° C 1- (4'-propylphenylethynyl) -4- (4 "
-Pentylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-propylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-butylphenylethynyl) -2,
5-difluorobenzene C-N point 101.4 ° C N-I point 169.9 ° C 1- (4'-butylphenylethynyl) -4- (4 "-
Pentylphenylethynyl) -2,5-difluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Hexylphenylethynyl) -2,5-difluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-butylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-pentylphenylethynyl)-
2,5-Difluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Hexylphenylethynyl) -2,5-difluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-pentylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-hexylphenylethynyl)-
2,5-Difluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Heptylphenylethynyl) -2,5-difluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-hexylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-heptylphenylethynyl)-
2,5-Difluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Octylphenylethynyl) -2,5-difluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-heptylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-octylphenylethynyl)-
2,5-Difluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Nonylphenylethynyl) -2,5-difluorobenzene 1- (4'-octylphenylethynyl) -4- (4 "
-Decylphenylethynyl) -2,5-difluorobenzene 1,4-bis (4'-nonylphenylethynyl) -2,
5-Difluorobenzene 1- (4'-nonylphenylethynyl) -4- (4 "-
Decylphenylethynyl) -2-fluorobenzene 1,4-bis (4′-decylphenylethynyl) -2,
5-Difluorobenzene (Example 7) [Compound (1-
Synthesis of g)] 5- (4'-butylphenylethynyl) -2- (4 "-
Preparation of cyanophenylethynyl) -1,4-difluorobenzene Steps 1 and 2) 4-steps similar to steps 6 and 7) of Example 4
Butylphenylacetylene was synthesized.

Steps 3 and 4) 2-Bromo-1,4-difluoro-4-iodobenzene was synthesized in the same manner as in Steps 3 and 4 of Example 6.

Step 5) 2-Bromo-1,4 in a nitrogen atmosphere
11 g of -difluoro-4-iodobenzene was dissolved in 16 ml of diethylamine, to which 0.03 g of bis (triphenylphosphine) palladium (II) chloride and 0.03 g of copper (I) iodide were added and stirred. The flask was cooled to 5 ° C. or lower, and 6.2 g of 4-butylphenylacetylene was added dropwise. After stirring at room temperature for 5 hours, the reaction solution was concentrated hydrochloric acid 9 ml and ice 20 g.
While mixing. After extraction with chloroform and washing with water twice, the chloroform was distilled off. Vacuum distillation of the residue (b.p170-1
80 ° C./5 mmHg) was carried out to obtain 8 g of 4-bromo-2,5-difluoro-4′-butyltran.

Steps 6 and 7) 4-cyanophenylacetylene was synthesized in the same manner as in Steps 6 and 7 of Example 2.

Step 8) 4-bromo-2,5 in a nitrogen atmosphere
-Difluoro-4'-butyltolan 5.2 g, 4-cyanophenylacetylene 1.9 g, triphenylphosphine
0.06 g and 0.04 g of bis (triphenylphosphine) palladium (II) chloride were dissolved in 33 ml of triethylamine, and 0.01 g of copper (I) iodide was added therein. afterwards,
Reflux for 5 hours. The reaction solution was poured into 300 ml of water, extracted with chloroform, washed twice with water, and then chloroform was distilled off. The residue was purified by silica gel-chloroform column chromatography and recrystallized from a mixed solvent of acetone and chloroform to give 5- (4'-butylphenylethynyl) -2- (4 "-cyanophenylethynyl) -1,4.
-2.9 g of difluorobenzene are obtained. C- of this compound
The N point was 145.5 ° C and the NI point was 250.1 ° C.

The following compounds were synthesized by the same method.

5- (4'-methylphenylethynyl)-
2- (4 "-cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-ethylphenylethynyl) -2- (4"-
Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-propylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-pentylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-hexylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-heptylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-octylphenylethynyl) -2- (4 "
-Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-nonylphenylethynyl) -2- (4 "-
Cyanophenylethynyl) -1,4-difluorobenzene 5- (4'-decylphenylethynyl) -2- (4 "-
Cyanophenylethynyl) -1,4-difluorobenzene (Example 8) [Liquid crystal composition] In order to compare the properties of the compound of the present invention and the existing compounds shown in Table 1, an ECH liquid crystal was used as a base liquid crystal and the compound of the present invention was used. A liquid crystal composition a containing Example 1 which is
Liquid crystal compositions b to d containing 10% of each of the liquid crystal compounds a and e were prepared in the following composition ratios.

[0081]

[Table 4]

Further, liquid crystal compositions e to l containing 10 to 30% of the compounds of the present invention as Examples 1 to 7 using the ECH liquid crystal as a base liquid crystal, which are currently generally used for the purpose of increasing Δn. A liquid crystal composition m containing the liquid crystal compound of
o was used as a comparative example, and the composition ratio was as follows.

[0083]

[Table 5]

[0084]

[Table 6]

[0085]

[Table 7]

Compositions a to o had NI points and birefringence (hereinafter Δ
n) was measured. The results are as follows.

[0087]

[Table 8]

Let us compare composition a and compositions b to d.
Composition a has a higher NI point than b and c. Also composition d
Since crystals were precipitated at room temperature, it was impossible to measure Δn. As described above, the liquid crystal composition a containing the compound of the present invention is the composition b to d containing the existing compound described in Table 1.
It can be seen that the liquid crystal composition has a wider liquid crystal temperature range than that of. Next, the liquid crystal compositions e to l containing the compound of the present invention and m to o containing the existing compound will be compared. The liquid crystal compositions e to l have a Δn of 0.03 to 0 compared to the liquid crystal compositions m to o.
It turned out to be about 11 large.

(Embodiment 9) [Liquid crystal display device] As shown in FIG. 1, an electrode 3 made of a transparent electrode film (for example, an ITO film) is formed on glass substrates 1 and 2 and made of polyimide or the like. Apply the alignment film. Next, the alignment control layer 4 is formed by rubbing, the glass substrates 1 and 2 are opposed to each other with a sealant 6 in between, and the liquid crystal compositions a to o prepared in Example 8 are injected between the glass substrates. A polarizing plate was attached to the outer surface of the substrate 1 and a reflective polarizing plate was attached to the outer surface of the substrate 2 to prepare TN type liquid crystal display panels A to O. At this time, the cell gap d of the liquid crystal display panel is the liquid crystal panels A to C.
Is 9.0 μ, and the liquid crystal panels E to O have Δ of each cell.
The value of n · d was set to be approximately 1.25 to 1.35.

The liquid crystal display cell thus prepared was subjected to AC static drive and was subjected to reflection type measurement, and the threshold voltage (hereinafter referred to as Vth) at 25 ° C. and the viewing angle dependence of voltage-light transmittance (hereinafter referred to as α). ), Steepness (hereinafter referred to as β), rising speed (hereinafter referred to as Tr), and falling speed (hereinafter referred to as Td) were measured. Note that α, β, V
th, is defined by the following equation.

[0091]

[Equation 1]

Further, Tr is the time required for turning on the voltage (at this time, the applied voltage is V90 (θ = 80 °)) to reduce the light transmittance to 10%, and Td is for turning off the voltage (at this time). The applied voltage was set to V10 (θ = 80 °) and expressed as the time required to restore 90% light transmittance. The measurement results were as follows.

[0093]

[Table 9]

A comparison between the liquid crystal panel A using the liquid crystal composition containing the liquid crystal compound of the present invention and the liquid crystal panels B and D using the existing liquid crystal compound containing compositions shown in Table 1 will be described. , Β value is small in the panel.
As a result, it can be seen that the panel A can be driven in high time division in TN display. Next, comparing liquid crystal panels E to L using the liquid crystal composition containing the liquid crystal compound of the present invention with liquid crystal panels M to O containing the existing liquid crystal compound, Tr + Td is equal to that of the liquid crystal panels E to L. 50 to 1
It turns out that it is about 50 ms faster.

Although the TN type liquid crystal display cell is used in the above embodiment, the same effect can be obtained when the STN type display cell is used.

[0096]

As described above, the compound of the present invention has good compatibility with other liquid crystal compounds, and when mixed with a general liquid crystal mixture, it has the effect of widening the practical temperature range and increasing Δn. is there. Therefore, by using the liquid crystal composition containing the liquid crystal compound of the present invention, a liquid crystal display device having a wide practical temperature range and a high response speed can be obtained. In these respects, the present invention is extremely effective as a basic component of a liquid crystal composition for STN type display, which is currently the mainstream of display devices.

[Brief description of drawings]

FIG. 1 is a diagram showing a liquid crystal display cell created in an example of the present invention.

[Explanation of symbols]

 1.2. Glass substrate 3. Transparent electrode 4. Orientation control layer 5. Polarizing plate 6. Sealant

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese Patent Application No. 5-49571 (32) Priority date Hei 5 (1993) March 10 (33) Priority claim country Japan (JP) (72) Inventor Mako Nakayama 3-5-3 Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (12)

[Claims] 1. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is a fluorine atom. In addition, Y represents a nitrile group or a linear alkyl group having 1 to 10 carbon atoms). 2. A general formula: (Wherein R1 and R2 each represent a straight-chain alkyl group having 1 to 10 carbon atoms).
The tolan derivative described in 1. 3. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms), The tolan derivative according to claim 1. 4. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms), The tolan derivative according to claim 1. 5. A general formula: (Wherein R1 and R2 each represent a straight-chain alkyl group having 1 to 10 carbon atoms).
The tolan derivative described in 1. 6. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms), The tolan derivative according to claim 1. 7. A general formula: (Wherein R1 and R2 each represent a straight-chain alkyl group having 1 to 10 carbon atoms).
The tolan derivative described in 1. 8. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms), The tolan derivative according to claim 1. 9. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is a fluorine atom. Further, Y represents at least one kind of tolan derivative represented by a nitrile group or a linear alkyl group having 1 to 10 carbon atoms), and a liquid crystal composition containing a tolan derivative. . 10. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is a fluorine atom. Further, Y represents a nitrile group or a tolan derivative represented by a linear alkyl group having 1 to 10 carbon atoms in an amount of 5 to 50% by weight of the general formula: (In the above formula, R ₁ and R _{2 each} represent a linear alkyl group having 1 to 10 carbon atoms, and the cyclohexane ring has a trans configuration). A cyclohexanecarboxylic acid phenyl ester derivative (hereinafter referred to as ECH system) The liquid crystal composition containing the tolan derivative according to claim 9, wherein the liquid crystal composition contains at least one kind of 30 to 80% by weight. 11. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is a fluorine atom. Y represents a nitrile group or a linear alkyl group having 1 to 10 carbon atoms) and at least one kind of tolan derivative represented by the general formula: (Wherein R ₁ and R _{2 each} represent a linear alkyl group having 1 to 10 carbon atoms, and the cyclohexane ring has a trans configuration), and at least one type of ECH system represented by 40 to 7
0 wt% General formula (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, and the cyclohexane ring has a trans configuration) and at least one compound having a positive dielectric anisotropy is represented by 1
The liquid crystal composition containing the tolan derivative according to claim 9, wherein the liquid crystal composition contains 0 to 50% by weight. 12. A general formula: (In the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, X ₁ , X ₂ , X ₃ and X ₄ each represent a fluorine atom or a hydrogen atom, but at least one X is a fluorine atom. Y represents a nitrile group or a linear alkyl group having 1 to 10 carbon atoms), and a liquid crystal composition containing at least one tolan derivative is used. A liquid crystal display device using a liquid crystal composition containing a characteristic tolan derivative.